GTM container ID not showing in source code

Hello, I installed the GTM Server Side plugin on my Wordpress website.
I set everything up according to your instructions: link
But when I looked in the source code, I don’t see the GTM-XXXXXXXX string anywhere, I also checked in dev tools → network but this string is not there either.
Everything seems fine through Tag Assistant, but it causes me a problem, for example, in Google Ads, when it doesn’t find the tag and my events are inactive (installation using the import of your containers from github).
Where could the problem be please?

This is not a problem, it is the result of using a custom loader that specifically modifies the GTM download request so that it is not blocked by adblockers and other means. You can find the GTM download request if you filter the network by your sGTM subdomain.
This usually looks something like this

More info about custom loader and adblockers